A Novel Active Cooling System for Internal Combustion Engine Using Shape Memory Alloy Based Thermostat

Abstract

Pollutants in exhaust gases and the high fuel consumption of internal combustion engines remain key issues in the automotive industry despite the emergence of electric vehicles. Engine overheating is a major cause of these problems. Traditionally, engine overheating was solved using electric pumps and cooling fans with electrically operated thermostats. This method can be applied using active cooling systems that are currently available on the market. However, the performance of this method is undermined by its delayed response time to activate the main valve of the thermostat and the dependence of the coolant flow direction control on the engine. This study proposes a novel active engine cooling system incorporating a shape memory alloy-based thermostat. After discussing the operating principles, the governing equations of motion were formulated and analyzed using COMSOL Multiphysics and MATLAB. The results show that the proposed method improved the response time required to change the coolant flow direction and led to a coolant temperature difference of 4.90 °C at 90 °C cooling conditions. This result indicates that the proposed system can be applied to existing internal combustion engines to enhance their performance in terms of reduced pollution and fuel consumption.

Design and Control of a Shape Memory Alloy-Based Idle Air Control Actuator for a Mid-Size Passenger Vehicle Application

“…It is the basic element used to calculate other spring parameters as expressed in Equation (1). It is an equation of modelling modified from a study conducted by Turabimana et al [13]. The parameters of the SMA spring were identified based on force (𝐹 ) that should extend to the full displacement of the SMA spring at its martensite phase.…”

“…This state of the actuator always occurs during engine idling conditions. The dynamic characteristics of air through the bypass and their corresponding engine idling characteristics are expressed in Equations ( 10)- (13). The main inputs of the equations forming the algorithms in this section include the actual parameters for the spark ignition engine from previous research with experiments [44][45][46] and practical engines [47,48].…”

“…Its shape memory effect (SME) and superelasticity make it suitable for various applications, including in the automotive sector. NiTi shape memory alloys are available on the market in different forms including cold-rolled strips and tubes [4][5][6], wires [7,8], sheets or plates [9,10], foils [11,12], and springs [10,13,14]. In different complicated actuators that use composite materials, shape memory alloy wires are embedded in the composite to improve their working ability, such as fast response in shape-changing of the structure, mechanical behaviour, and impactful actuation [15,16].…”

“…In the automotive industry, they are applied in adaptive shock control actuators [22,23]. The actuators with improved stroke and fast actuation responses use spring-based shape memory alloys [13,24]. SMA spring actuators are mostly applied in the automotive sector.…”

“…The findings describe the reduction in the actuation time of 95% with a 62% weight reduction compared to the dome-shaped steel fender skirt. Pacifique et al [13] proposed an active thermostat that uses an SMA spring to activate its operations. The design covers mathematical modelling and simulation, which show an engine overheating reduction and low-pressure fluctuation in the cooling system.…”